Remotely controlled insulin pumps may be used for the continuous subcutaneous infusion of insulin to patients with diabetes. The insulin, which may be present in a reservoir of the insulin pump, can be conveyed into the patient's body according to a patient and time-of-day dependent basal delivery schedule via a subcutaneous cannula. In addition to this basal delivery, bolus insulin delivery may be performed out of the same reservoir on demand such as, for example, for compensating carbohydrate intake and for correcting undesirably raised blood glucose values. Some modern insulin pumps have programmable remote controllers that can comprise a design similar to a cell phone or a PDA. Alternatively, a standard device such as a cell phone or a PDA may be used as the remote controller itself. For those insulin pumps, the user interface of the insulin pump itself may be limited or missing.
Insulin pumps which are designed to be fully remote controlled may be disposable pumps which are designed to be used for a number of days and to be disposed afterwards. When such a pump is replaced, an infusion program including all required control data, such as the basal delivery schedule, the date and the time of day may be transferred onto the new pump from the remote controller. Prior to this transfer, the memory of the insulin pump comprises the control firmware but no patient-specific infusion program.
Some insulin pumps can be designed as patch pumps which are carried by the patient directly at the infusion site and can be fixed to the skin by an adhesive layer. Those pumps can comprise a cannula and an automatic inserter which automatically inserts the cannula into to patient's subcutaneous tissue from an initially retracted position inside the housing. Those pumps may also be provided with a readily built-in reservoir which is filled by the patient prior to use and readily built-in battery. After a using time of some days, the pump can be disposed as a whole.
For fully remote controlled insulin pumps, the remote controller may be required for all user operations such as programming the delivery of an insulin bolus or replacing the pump by a new one. However, in some situations a remote controller may not be available. This may be the case, for example, when the remote controller is defective, lost or forgotten, e.g., when traveling. Accordingly, a need exists for alternative insulin delivery systems such as those including a first insulin pump and a second insulin pump for continuous therapy.